1. Field of the Invention
This invention relates generally to the field of pressure vessels and specifically to a diffuser and air cell retainer therefor.
2. Description of the Related Art
Liquid dispensing systems often use pressure vessels, such as accumulators or pressure control devices for holding a liquid. Commonly, a pipe extends into a water source, such as a well. A pump forces water from the well, through the pipe, and into the pressure vessel. Water is then distributed from the pressure vessel, as needed, to a household water system, for example. One type of pressure vessel is shown in U.S. Pat. No. 4,785,956 to Kepler et al., which is incorporated herein by reference.
The pressure vessel, or tank, includes an inflatable air cell, such as a bag, therein with an inflating valve extending through one end of the vessel. An inlet and outlet port in fluid communication with the water system is provided at the other end of the vessel. As water is pumped into the vessel, the bag is forced upwardly by the incoming water. The upward movement of the bag tends to form a crease thereby causing excessive wear and premature failure of the bag.
U.S. Pat. No. 4,214,611 to Takacs, incorporated herein by reference, shows a tie-down system for the bag. The tie-down holds the center bottom part of the bag in place to more evenly distribute the flexing force on the bag. Such a tie-down has been effective in prolonging bag life, but has proven somewhat difficult to assemble and disassemble. In addition, the tie-down can only be used in tanks having a threaded port. The tie-down also projects into the tank.
Typically, the bags are removed and replaced during the life of the pressure vessel. Thus, it would be desirable to have a tie-down which is easy to assemble. The tie-down should also serve to diffuse water at the point of entry into the vessel to protect the bag from the force of direct flow. The tie-down should also use a minimum amount of space and should be useful in tanks having a neck and a flange at the inlet and outlet port.